This is the next-to-last of the five quotes I’ve gotten from philosopher Walter Kaufmann’s great book, The Faith of a Heretic (Doubleday, 1961). This is from page 147.
“If a philosopher takes the attitude that Plato and Kant must be defended at all costs, if necessary by the most farfetched interpretations, and that their works must be read as we should not read those of any other philosopher, this would be a personal defect; it is certainly not the essence of philosophy. On the contrary, his approach would be patently unphilosophical. In theology, on the other hand, such partiality, such special pleading, such a double standard is institutionalized.”